In recent years, there is introduced a new viewing style for television. In the new viewing style, an ultra-slim large-screen television such as a liquid crystal television, which is capable of displaying high quality image and playing high quality sound, is hung on a wall or mounted on a television stand for mounting the television against wall, and displays a still image of a painting, a picture, etc. (which is called generally as an “ornamental image”) to enjoy the displayed image when not viewing a television image.
Therefore, for example in a large-screen television, there is a further demand for technique for displaying an ornamental image or the like by power-saving drive for driving as low power as possible.
Various techniques for televisions have been already proposed for realizing power-saving drive depending on differences between usage statuses regardless of whether or not the ornamental image or the like is displayed.
For example, Patent Literature 1 discloses a technique for providing a power reduction apparatus for a liquid crystal television receiver, being capable of switching its power supply between a battery and a power supply adapter. The power reduction apparatus determines which one of the battery and the power supply adapter is used as the power supply. When the battery is selected as the power supply, the power reduction apparatus causes a backlight unit to perform backlighting at low brightness, and when the power supply adapter is selected, the power reduction apparatus causes the backlight unit to perform the backlighting at high brightness.
Further, Patent Literature 2 discloses a technique for controlling, in a liquid crystal television, brightness of a backlight unit and power distribution status for a liquid crystal display processing section, depending on a result of determination for determining whether or not a video signal detection circuit detects a video signal to be displayed.
Furthermore, Patent Literature 3 discloses a technique for improving visibility for a moving image while realizing low power consumption by controlling a backlight unit. Specifically, brightness of the backlight unit is adjusted depending on the kinds of the images to be displayed. For a still image and a moving image displayed together on a display screen, elongatedness of display data of the still image is different from that of the moving image, so that the moving image becomes higher in surface brightness than the still image.